An organic electroluminescent compound and its preparation method and application

Abstract

The present invention relates to the technical field of organic electroluminescent materials, and in particular to an organic electroluminescent compound and a preparation method and application thereof; the organic electroluminescent compound has a structure as shown in Formula I, and the organic electroluminescent compound is endowed with a higher glass transition temperature and good thermal stability through the design of the molecular structure and substituents, thereby avoiding its degradation in a high-temperature deposition process; and the hole transport performance and stability of the organic electroluminescent compound as a hole transport layer are significantly improved, so that an OLED device containing the organic electroluminescent compound has high luminous efficiency and long service life, and improves power efficiency and power consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescent materials, and in particular to an organic electroluminescent compound and a preparation method and application thereof. Background Art

[0002] Electroluminescent devices (EL devices) are self-luminous devices with the advantages of having a wider viewing angle, a larger contrast ratio and a faster response time. At present, the first organic EL device was developed by Eastman Kodak by using aromatic diamine small molecules and metal aluminum complexes as materials for forming the light-emitting layer [Appl. Phys. Lett. 51, 913, 1987].

[0003] In the prior art, hole transport materials are usually used in hole transport layers or hole injection layers. Common hole transport materials are triarylamine derivatives, which contain at least two triarylamine groups or at least one triarylamine group and at least one carbazole group; the above compounds are usually derived from diarylamino-substituted triphenylamine (TPA type), diarylamino-substituted biphenyl derivatives (TAD type) or a combination of these basic compounds. When the above compounds are used in fluorescent OLEDs or phosphorescent OLEDs, especially in organic electroluminescent devices, the operating voltage, efficiency, life, and thermal stability during sublimation need to be improved.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an organic electroluminescent compound and a preparation method and application thereof.

[0006] As a first object of the present invention, an organic electroluminescent compound intermediate is provided; the intermediate can be used to synthesize an organic electroluminescent compound.

[0007] Specifically, the organic electroluminescent compound has a structure as shown in Formula M-1:

[0008]

[0009] As a second object of the present invention, a method for preparing the above-mentioned organic electroluminescent compound intermediate is provided, and the synthetic route is as follows:

[0010]

[0011] The specific steps include:

[0012] (1) Compound IM-01 is used as a raw material, and is subjected to a coupling reaction with o-chloroaniline in the presence of a catalyst to obtain compound IM-02;

[0013] (2) subjecting compound IM-02 to a ring-closing reaction under the action of a catalyst to obtain the organic electroluminescent compound intermediate having a structure as shown in formula M-1;

[0014] Preferably, in step (1) and step (2), the catalyst is a palladium catalyst;

[0015] Further, in step (1), the catalyst is Pd2(dba)3;

[0016] Furthermore, in step (2), the catalyst is palladium acetate.

[0017] The use of the palladium catalyst is more conducive to the ring-closing reaction and improves the synthesis efficiency of the organic electroluminescent compound intermediate.

[0018] As a third object of the present invention, an organic electroluminescent compound is provided; the organic electroluminescent compound has good hole transport performance and stability, and can be used to manufacture OLED devices with a longer working life.

[0019] Specifically, the organic electroluminescent compound has a structure as shown in Formula I:

[0020]

[0021] Wherein, Ar1, Ar2, and Ar3 each independently represent a C6-C 60 Aromatic or C6~C 60 Heteroaromatic ring system.

[0022] Preferably, Ar1, Ar2, and Ar3 each independently represent benzene, biphenyl, naphthalene, phenanthrene, fluorene, dibenzofuran or dibenzothiophene.

[0023] Preferably, the organic electroluminescent compound is selected from one or more of Formula H1 to Formula H12:

[0024]

[0025]

[0026] As a fourth object of the present invention, a method for preparing the above-mentioned organic electroluminescent compound is provided, comprising the following steps:

[0027] (1) As raw material, it is subjected to coupling reaction with Ar1-X under the action of catalyst to obtain

[0028] (2) As raw materials, The coupling reaction is carried out under the action of a catalyst to obtain

[0029] Wherein, X represents a halogen;

[0030] Ar1, Ar2, and Ar3 each independently have the same definition as in Formula I above.

[0031] Preferably, in step (1), the catalyst is a copper catalyst; preferably cuprous iodide;

[0032] Preferably, in step (2), the catalyst is a palladium catalyst; preferably Pd2(dba)3;

[0033] Preferably, X represents I.

[0034] As a fifth object of the present invention, a hole transport layer for an OLED device is provided, wherein the hole transport layer comprises the above-mentioned organic electroluminescent compound.

[0035] As a sixth object of the present invention, an OLED device is provided, the OLED device comprising an anode, a cathode and at least one organic thin film layer located between the anode and the cathode; the organic thin film layer comprises a hole transport layer, and any one or a combination of at least two of a hole injection layer, an electron blocking layer, a hole blocking layer, a light emitting layer, an electron transport layer and an electron injection layer;

[0036] The hole transport layer is the hole transport layer for the OLED device as described above.

[0037] As a seventh object of the present invention, an electronic device is provided, comprising the OLED device as described above.

[0038] Excellent effects of the present invention:

[0039] (1) The organic electroluminescent compound provided by the present invention has a condensed ring structure. The design of the molecular structure and substituents gives the organic electroluminescent compound a higher glass transition temperature and good thermal stability, thereby avoiding its degradation in a high-temperature deposition process; and significantly improves its hole transport performance and stability as a hole transport layer, so that the OLED device containing it has high luminous efficiency and long working life, and improves power efficiency and power consumption.

[0040] (2) The organic electroluminescent compound of the present invention is suitable for fluorescent OLED devices and phosphorescent OLED devices, especially for phosphorescent OLED devices. DETAILED DESCRIPTION

[0041] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0042] The structures of the compounds involved are as follows:

[0043]

[0044] Example 1

[0045] This embodiment provides an organic electroluminescent compound intermediate M-1, the structure of which is as follows:

[0046]

[0047] The synthetic route of the M-1 is as follows:

[0048]

[0049] The specific steps include:

[0050] (1) Synthesis of IM-02:

[0051]

[0052] In a 1000ml three-necked flask, add 3,6-dibromo-9,9-dimethylfluorene (35.2g, 0.1mol) and o-chloroaniline (12.8g, 0.1mol), add 500ml toluene, add sodium tert-butoxide (12.5g, 0.13mol) under stirring, then add Pd2(dba)3 (0.23g, 0.00025mol), replace nitrogen, add 1g of 10% toluene solution of tri-tert-butylphosphine, start heating, slowly raise the temperature to 80℃ (keep nitrogen protection during the reaction process), react for 2 hours, HPLC detection (raw material 3,6-dibromo-9,9-dimethylfluorene <1%), stop the reaction, and cool to room temperature. After the reaction is completed, cool to 25℃, wash twice with brine, and add anhydrous sodium sulfate to the organic phase for drying. Column chromatography, use toluene as the eluent. The crude product was concentrated to obtain a crude product, which was recrystallized using toluene:ethanol = 1:2 to obtain 33.9 g of intermediate IM-02 with a purity of >98% and a yield of 85%.

[0053] (2) Synthesis of M-1:

[0054]

[0055] In a 1000ml three-necked flask, add IM-02 (33.9g, 0.085mol), add DMA (500ml), add palladium acetate (0.95g, 0.0043mol), potassium carbonate (17.6g, 0.13mol), replace nitrogen, add tri-tert-butylphosphine 10% toluene solution (17.2g, 0.0085mol), slowly heat to 130°C, react for 3 hours, HPLC detection (IM-02<1%), stop the reaction. Cool the reaction to room temperature, add 1000ml water, a large amount of solid precipitates, filter to obtain a solid crude product, recrystallize with toluene: ethanol = 1:4 to obtain 18.5g of intermediate M-1, purity 98%, yield 60%.

[0056] Example 2

[0057] This embodiment provides an organic electroluminescent compound H1, the structure of which is as follows:

[0058]

[0059] The preparation method of H1 comprises the following steps:

[0060] (1) Synthesis of M-1-1:

[0061]

[0062] In a 250ml three-necked flask, add M-1 (3.6g, 0.01mol) and iodobenzene (2.1g, 0.01mol), add DMF 100ml, add potassium hydroxide (1.1g, 0.02mol), cuprous iodide (1.9g, 0.01mol) under stirring, heat to 150°C for 3 hours, HPLC detection (M-1<1%), stop the reaction. Cool the reaction solution, add 200ml water, solid precipitates, filter to obtain a crude product, recrystallize from toluene, and obtain 3.5g of intermediate M-1-1 with a purity of 98% and a yield of 80%.

[0063] (2) Synthesis of H1:

[0064]

[0065] In a 250ml three-necked flask, add M-1-1 (3.5g, 0.008mol) and di(4-biphenyl)amine (2.57g, 0.008mol), add 100ml toluene to dissolve, add sodium tert-butoxide (1g, 0.0104mol), Pd2(dba)3 (0.037g, 0.00004mol), replace nitrogen, add 0.16g of 10% toluene solution of tri-tert-butylphosphine, start heating, slowly raise the temperature to 80°C (keep nitrogen protection during the reaction process), react for 2 hours, HPLC detection (M-1-1<1%), stop the reaction, and cool to room temperature. After the reaction is completed, cool to 25°C, wash with brine twice, add anhydrous sodium sulfate to the organic phase and dry; column chromatography, use toluene as eluent; concentrate to obtain a crude product, recrystallize from toluene to obtain 4.3g product H1, purity>99%, yield 80%.

[0066] The H1 compound was detected by mass spectrometry and the m / z was measured to be 680.

[0067] The H1 compound was tested by NMR, and the data analysis is as follows:

[0068] 1 HNMR (300MHz, CDCl3) δ8.55 (d, 1H), δ8.24 (s, 1H), δ7.96~7.94 (m, 2H), δ7.75~7.70 (m, 5H), δ7.62~7.35 (m, 21H), δ7.16 (m, 2H), δ1.69 (s, 6H).

[0069] Example 3

[0070] This embodiment provides an organic electroluminescent compound H2, the structure of which is as follows:

[0071]

[0072] The preparation method of H2 comprises the following steps:

[0073] (1) Synthesis of M-1-1:

[0074] Same as Example 2.

[0075] (2) Synthesis of H2:

[0076]

[0077] In a 250 ml three-necked flask, add M-1-1 (3.5 g, 0.008 mol) and N-[1,1'-biphenyl-4-yl]-9,9-dimethyl-9H-fluorene-2-amine (2.9 g, 0.008 mol), add 100 ml of toluene to dissolve, add sodium tert-butoxide (1 g, 0.0104 mol) and Pd2(dba)3 (0.037 g, 0.00004 mol), replace nitrogen, add 0.16 g of 10% toluene solution of tri-tert-butylphosphine, start heating, slowly raise the temperature to 80°C (keep nitrogen protection during the reaction process), react for 2 hours, detect by HPLC (M-1-1<1%), stop the reaction, and cool to room temperature. After the reaction, cool to 25°C, wash twice with brine, add anhydrous sodium sulfate to the organic phase and dry it; perform column chromatography using toluene as the eluent; concentrate to obtain a crude product, and recrystallize with toluene to obtain 4.6 g of product H2 with a purity of >99% and a yield of 80%.

[0078] The H2 compound was detected by mass spectrometry and the m / z was measured to be 720.

[0079] The H2 compound was tested by NMR, and the data analysis is as follows:

[0080] 1 HNMR (300MHz, CDCl3) δ8.55 (d, 1H), δ8.24 (s, 1H), δ7.96~7.86 (m, 4H), δ7.75~ 7.70 (m, 4H), δ7.62~7.28 (m, 17H), δ7.16 (m, 3H), δ1.69 (s, 6H), δ1.65 (s, 6H).

[0081] Example 4

[0082] This embodiment provides an organic electroluminescent compound H5, the structure of which is as follows:

[0083]

[0084] The preparation method of H5 comprises the following steps:

[0085] (1) Synthesis of M-1-2:

[0086]

[0087] In a 250ml three-necked flask, add M-1 (3.6g, 0.01mol) and 4-iodobiphenyl (2.8g, 0.01mol), add 100ml of DMF, add potassium hydroxide (1.1g, 0.02mol) and cuprous iodide (1.9g, 0.01mol) under stirring, heat to 150°C and react for 3 hours. HPLC detection (M-1<1%), stop the reaction, cool the reaction solution, add 200ml of water, solid precipitates, filter to obtain a crude product, and recrystallize from toluene to obtain 4.1g of intermediate M-1-2 with a purity of 98% and a yield of 80%.

[0088] (2) Synthesis of H5:

[0089]

[0090] In a 250 ml three-necked flask, add M-1-2 (4.1 g, 0.008 mol) and N-[1,1'-biphenyl-4-yl]-9,9-dimethyl-9H-fluorene-2-amine (2.9 g, 0.008 mol), add 100 ml of toluene to dissolve, add sodium tert-butoxide (1 g, 0.0104 mol) and Pd2(dba)3 (0.037 g, 0.00004 mol), replace nitrogen, add 0.16 g of 10% toluene solution of tri-tert-butylphosphine, start heating, slowly raise the temperature to 80°C (keep nitrogen protection during the reaction process), react for 2 hours, detect by HPLC (M-1-2 <1%), stop the reaction, and cool to room temperature. After the reaction, cool to 25°C, wash twice with brine, add anhydrous sodium sulfate to the organic phase and dry it; perform column chromatography using toluene as the eluent; concentrate to obtain a crude product, and recrystallize with toluene to obtain 5.1 g of product H5 with a purity of >99% and a yield of 80%.

[0091] The H5 compound was detected by mass spectrometry and the m / z was measured to be 796.

[0092] The H5 compound was tested by NMR, and the data analysis is as follows:

[0093] 1 HNMR (300MHz, CDCl3) δ8.55 (d, 1H), δ8.24 (s, 1H), δ7.96~7.86 (m, 8H), δ7.75~ 7.70 (m, 6H), δ7.55~7.28 (m, 15H), δ7.16 (m, 3H), δ1.69 (s, 6H), δ1.65 (s, 6H).

[0094] Example 5

[0095] This embodiment provides an organic electroluminescent compound H8, the structure of which is as follows:

[0096]

[0097] The preparation method of H8 comprises the following steps:

[0098] (1) Synthesis of M-1-3:

[0099]

[0100] In a 250ml three-necked flask, add M-1 (3.6g, 0.01mol) and 3-iodobiphenyl (2.8g, 0.01mol), add 100ml of DMF, add potassium hydroxide (1.1g, 0.02mol) and cuprous iodide (1.9g, 0.01mol) under stirring, heat to 150°C and react for 3 hours. HPLC detection (M-1<1%), stop the reaction, cool the reaction solution, add 200ml of water, solid precipitates, filter to obtain a crude product, and recrystallize from toluene to obtain 4.1g of intermediate M-1-3 with a purity of 98% and a yield of 80%.

[0101] (2) Synthesis of H8:

[0102]

[0103] In a 250 ml three-necked flask, add M-1-3 (4.1 g, 0.008 mol) and N-[1,1'-biphenyl-4-yl]-9,9-dimethyl-9H-fluorene-2-amine (2.9 g, 0.008 mol), add 100 ml of toluene to dissolve, add sodium tert-butoxide (1 g, 0.0104 mol) and Pd2(dba)3 (0.037 g, 0.00004 mol), replace nitrogen, add 0.16 g of 10% toluene solution of tri-tert-butylphosphine, start heating, slowly raise the temperature to 80°C (keep nitrogen protection during the reaction process), react for 2 hours, detect by HPLC (M-1-3<1%), stop the reaction, and cool to room temperature. After the reaction, cool to 25°C, wash twice with brine, add anhydrous sodium sulfate to the organic phase and dry it; perform column chromatography using toluene as the eluent; concentrate to obtain a crude product, and recrystallize with toluene to obtain 5.1 g of product H8 with a purity of >99% and a yield of 80%.

[0104] The H8 compound was detected by mass spectrometry and the m / z was measured to be 796.

[0105] The H8 compound was tested by NMR, and the data analysis is as follows:

[0106] 1HNMR (300MHz, CDCl3) δ8.55 (d, 1H), δ8.24 (s, 1H), δ8.21 (s, 1H), δ7.96~7.86 (m, 4H), δ7.75~7.68(m,7H), δ7.60~7.28(m,17H), δ7.16(m,3H), δ1.69(s,6H), δ1.65(s,6H).

[0107] Example 6

[0108] This embodiment provides an organic electroluminescent compound H9, the structure of which is as follows:

[0109]

[0110] The preparation method of H9 comprises the following steps:

[0111] (1) Synthesis of M-1-3:

[0112] Same as Example 5.

[0113] (2) Synthesis of H9:

[0114]

[0115] In a 250 ml three-necked flask, add M-1-3 (4.1 g, 0.008 mol) and N-[1,1'-biphenyl-3-yl]-9,9-dimethyl-9H-fluorene-2-amine (2.9 g, 0.008 mol), add 100 ml of toluene to dissolve, add sodium tert-butoxide (1 g, 0.0104 mol) and Pd2(dba)3 (0.037 g, 0.00004 mol), replace nitrogen, add 0.16 g of 10% toluene solution of tri-tert-butylphosphine, start heating, slowly raise the temperature to 80°C (keep nitrogen protection during the reaction process), react for 2 hours, detect by HPLC (M-1-3<1%), stop the reaction, and cool to room temperature. After the reaction, the mixture was cooled to 25°C, washed twice with brine, and the organic phase was dried by adding anhydrous sodium sulfate; column chromatography was performed using toluene as the eluent; the crude product was concentrated to obtain a crude product, which was recrystallized from toluene to obtain 5.1 g of product H9 with a purity of >99% and a yield of 80%.

[0116] The H9 compound was detected by mass spectrometry and the m / z was measured to be 796.

[0117] The H9 compound was tested by NMR, and the data analysis is as follows:

[0118] 1HNMR (300MHz, CDCl3) δ8.55 (d, 1H), δ8.24 (s, 1H), δ8.21 (s, 1H), δ7.96~7.86 (m, 4H), δ7 .75~7.68(m, 7H), δ7.60~7.28(m, 15H), δ7.18~7.16(m, 5H), δ1.69(s, 6H), δ1.65(s, 6H).

[0119] Application Example 1

[0120] This application example provides an OLED device, and the preparation method of the OLED device is as follows:

[0121] (1) A transparent electrode indium tin oxide (ITO) film (15 Ω / sq, Samsung Corning, South Korea) on a glass substrate for an organic light emitting diode (OLED) device was ultrasonically cleaned with trichloroethylene, acetone, ethanol, and distilled water in sequence and then stored in isopropyl alcohol; the ITO substrate was mounted on a substrate fixture of a vacuum vapor deposition apparatus.

[0122] (2) The compound HIL is introduced into the chamber of a vacuum vapor deposition apparatus, and the chamber pressure of the apparatus is then controlled to reach 10 -6 A current was applied into the chamber to evaporate the introduced substances, thereby forming a hole injection layer with a thickness of 60 nm on the ITO substrate.

[0123] (3) The organic electrogenic compound H1 provided by the present invention is introduced into another chamber of the vacuum vapor deposition equipment, and current is applied to the chamber to evaporate the compound, thereby forming a hole transport layer with a thickness of 20 nm on the hole injection layer.

[0124] (4) Compound CBP was introduced into one chamber of a vacuum vapor deposition device as a matrix material, and compound D-1 was introduced into another chamber as a dopant; the two materials were evaporated at different rates and deposited at a doping amount of 15 wt % (based on the total weight of the matrix material and the dopant), thereby forming a light-emitting layer with a thickness of 30 nm on the hole transport layer.

[0125] (5) Compound ETL was introduced into one chamber, and 8-hydroxyquinoline lithium (lithium quinolate) was introduced into another chamber; the two materials were evaporated at the same rate and deposited at a doping amount of 50 wt % respectively, thereby forming an electron transport layer with a thickness of 30 nm on the light-emitting layer.

[0126] (6) On the electron transport layer, 8-hydroxyquinoline lithium was deposited with a thickness of 2 nm as the electron injection layer EIL.

[0127] (7) Depositing an Al cathode with a thickness of 150 nm on the electron injection layer by another vacuum vapor deposition device; obtaining the OLED device.

[0128] All the materials used in the preparation of the OLED devices were -6 Purification was performed by vacuum sublimation at 400 torr conditions.

[0129] Application Example 2

[0130] This application example provides an OLED device, which differs from application example 1 in that H1 in step (3) is replaced by H2.

[0131] Application Example 3

[0132] This application example provides an OLED device, which differs from application example 1 in that H1 in step (3) is replaced by H4.

[0133] Application Example 4

[0134] This application example provides an OLED device, which differs from application example 1 in that H1 in step (3) is replaced by H5.

[0135] Application Example 5

[0136] This application example provides an OLED device, which differs from application example 1 in that H1 in step (3) is replaced by H7.

[0137] Application Example 6

[0138] This application example provides an OLED device, which differs from application example 1 in that H1 in step (3) is replaced by H8.

[0139] Application Example 7

[0140] This application example provides an OLED device, which differs from application example 1 in that H1 in step (3) is replaced by H11.

[0141] Comparative Example 1

[0142] This comparative example provides an OLED device, which is different from Application Example 1 in that H1 in step (3) is replaced by HTL.

[0143] Performance testing of OLED devices

[0144] The OLED-1000 multi-channel accelerated aging life and photochromic performance analysis system produced by Hangzhou Yuanfang was used to test the driving voltage, current efficiency and life LT90 of the OLED devices provided in Application Examples 1 to 7 and Comparative Example 1; wherein LT90 refers to the time required for the brightness to drop to 90% of the original brightness while keeping the current density unchanged.

[0145] The specific test results are shown in Table 1:

[0146] Table 1

[0147]

[0148]

[0149] It can be seen from Table 1 that, compared with the organic electroluminescent compounds in the prior art, the organic electroluminescent compounds of the present invention have excellent properties, so the organic electroluminescent device provided by the present invention has high luminous efficiency and long service life; and the organic electroluminescent device requires a low driving voltage, thereby improving power efficiency and power consumption.

[0150] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. An organic electroluminescent compound, characterized in that: The organic electroluminescent compound is selected from Formula H1 or Formula H4: 。 2. A hole transport layer for an OLED device, characterized in that: The hole transport layer comprises the organic electroluminescent compound according to claim 1 .

3. An OLED device, characterized in that: The OLED device comprises an anode, a cathode and at least one organic thin film layer located between the anode and the cathode; the organic thin film layer comprises a hole transport layer, and any one or a combination of at least two of a hole injection layer, an electron blocking layer, a hole blocking layer, a light emitting layer, an electron transport layer and an electron injection layer; The hole transport layer is the hole transport layer for an OLED device as claimed in claim 2.

4. An electronic device, characterized in that: The electronic device comprises the OLED device according to claim 3.

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